Multi-layer wearable body armor

ABSTRACT

A multi-layer body armor plate includes a strike plate; a mesh layer positioned over the strike plate, the mesh layer having a number of open cells; and an outer skin layer positioned over the mesh layer so as to encapsulate the open cells of the mesh layer between the strike plate and the outer skin layer. The open cells of the mesh layer may entrap air or may be filled with expandable, buoyant foam.

RELATED APPLICATION

The present application is a continuation application and claimspriority of co-pending U.S. application Ser. No. 16/687,969, filed Nov.19, 2019, entitled MULTI-LAYER WEARABLE BODY ARMOR, which claimspriority to previously co-pending U.S. application Ser. No. 16/208,676,filed Dec. 4, 2018, entitled MULTI-LAYER WEARABLE BODY ARMOR, which wasissued as U.S. Pat. No. 10,591,257 on Mar. 17, 2020, both of which arehereby incorporated by reference into the present application in theirentireties.

GOVERNMENT INTERESTS

This invention was developed with government support under Contract No.DE-NA0000622 awarded by the United States Department of Energy.Accordingly, the U.S. Government has certain rights in the invention.

BACKGROUND

The present invention relates to body armor for protecting wearers frombullets and other ballistic projectiles.

Conventional body armor typically includes ceramic or steel platesembedded in vests or other articles of clothing. Although effective inmany applications, ceramic and steel body armor plates suffer fromlimitations that limit their utility. For example, ceramic body armorplates are relatively thick and therefore limit wearers' mobility andability to quickly reach firearms, radios, and other equipment. Ceramicbody armor plates are also expensive and cannot be easily sized andshaped to conform to a particular wearer's physique. Ceramic body armorplates are also brittle and often crack when struck by projectiles. Suchcracking makes them less effective at protecting against subsequentprojectile strikes in the same area.

Steel body armor plates are often thinner than ceramic plates andtypically don't crack as easily. But steel plates are heavy andtherefore limit their wearers' mobility. And, as with ceramic plates,steel body armor plates are not easily sized and shaped to conform to aparticular wearer's physique. Steel body armor plates also sometimescause secondary injuries when projectiles fragment and “splash” off themand strike their wearers or others nearby. Another problem with bothceramic and steel body armor plates is they are so negatively buoyantthat they can't be safely used in body armor that may be worn in or neardeep bodies of water.

SUMMARY

The present invention solves the above-described problems and otherproblems with conventional body armor by providing a multi-layer bodyarmor plate that is thinner and lighter than ceramic or steel body armorplates, more effective against projectile fragmentation, capable ofwithstanding multiple projectile hits, more easily sized and shaped toconform to a particular wearer's physique, and less negatively buoyantand therefore safer to wear in or near bodies of water.

A body armor plate constructed in accordance with an embodiment of theinvention broadly comprises a strike plate; a mesh layer positioned overthe strike plate; and an outer skin layer positioned over the meshlayer. The strike plate is worn closest to a wearer's torso or otherbody part. The mesh layer covers the outer face of the strike plate andhas repeating and intersecting walls that define a number of open cells.The outer skin layer covers the mesh layer and encapsulates the opencells in the mesh layer.

The layers of the body armor plate cooperate to arrest projectilefragments and reduce injuries from fragmentation. Specifically, when aprojectile strikes the body armor plate, it first penetrates, but isslowed by, the outer skin layer and the mesh layer. When it strikes thestrike plate, it may fragment, but the fragments are slowed by andtrapped within the mesh layer. This prevents the fragments fromsplashing off the body armor plate and injuring the wearer and/or othersnearby.

The mesh layer, and particularly the trapped air in the mesh layer,reduce the negative buoyancy of the body armor plate so that it is saferto wear in or near bodies of water than steel or ceramic plates. Thebody armor plate is also lighter than ceramic or solid metal body armorplates.

In one embodiment, the strike plate is formed of a metal matrixcomposite material using additive manufacturing techniques. The meshlayer and outer skin layer may also be co-formed with the strike platevia the same additive manufacturing process or may be formed separatelyand adhered to the strike plate. Forming some or all of the layers ofthe body armor via additive manufacturing permits the body armor to besized and shaped to conform to a particular wearer's physique. Moreover,additive manufacturing permits the thicknesses of the strike plate andother layers to be selected to provide protection against differenttypes and speeds of ballistic projectiles.

An embodiment of the metal matrix composite material comprises a metalmatrix and nanocellulose supplement. Use of such a metal matrixcomposite material allows the layers of the body armor plate to berelatively thin and lightweight while still providing sufficientprotection against projectiles. This material also resists cracking andthus protects against multiple ballistic strikes in the same area.

Some embodiments of the body armor plate may also include an expandable,buoyant foam that at least partially fills the open cells of the meshlayer. In other embodiments, the open cells simply trap air inside thebody armor plate.

Embodiments of the invention may also include a vest or other wearablearticle of clothing in which one or more of the above-described bodyarmor plates may be supported over a wearer's torso or other body part.The body armor plates may also be applied to or embedded within otherobjects such as vehicle door panels, walls, ceilings, etc.

This summary is provided to introduce a selection of concepts in asimplified form that are further described in the detailed descriptionbelow. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the present invention will be apparent from thefollowing detailed description of the embodiments and the accompanyingdrawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Embodiments of the present invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a partial vertical cross-sectional view of a body armor plateconstructed in accordance with an embodiment of the present invention.

FIG. 2 is a front elevational view of the body armor plate of FIG. 1with portions hidden to reveal interior features.

FIG. 3 is a flow diagram depicting steps in a method of making acomposite material that may be used to fabricate the body armor plate.

FIG. 4 is a flow diagram depicting steps in a method of fabricating thebody armor plate via an additive manufacturing process.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION

Embodiments of the present invention provide a body armor plate formedof multiple layers that are cooperatively configured so as to be thinnerand lighter than ceramic or steel body armor plates, more effectiveagainst projectile fragmentation, capable of withstanding multipleprojectile hits, and less negatively buoyant and therefore safer to wearin or near bodies of water. Some or all of the layers of the body armorplate may be formed via additive manufacturing techniques so that thebody armor plate may be more easily sized and shaped to conform to aparticular wearer's physique. The plates are preferably formed of ametal matrix composite material that is stronger and lighter than manyconventional materials.

Specific embodiments of the body armor plate will now be described withreference to the attached drawing figures. Turning now to FIGS. 1 & 2, abody armor plate 10 constructed in accordance with embodiments of theinvention is illustrated and broadly comprises a strike plate 12; a meshlayer 14 positioned over the strike plate 12; and an outer skin layer 16positioned over the mesh layer 14. Each of these layers are described inmore detail below.

Some embodiments of the body armor plate may also comprise expandable,buoyant foam 18 that at least partially fills voids in the mesh layer.In other embodiments, the voids in the mesh layer are filled withentrapped air instead.

The strike plate 12 has an inner face 20 for at least partially coveringthe wearer's chest, back, or other body portion and an outer strike face22 that may be impacted by a ballistic projectile. As shown in FIG. 2,concave reliefs 24, 26 may be formed in the upper corners of the strikeplate 12 for accommodating the wearer's arms. Similar concave reliefs28, 30 may be formed in the lower corners of the strike plate 12 foraccommodating the wearer's hips and thighs. In one embodiment, thestrike plate has a multi-curved profile for conforming to the wearer'storso. Specifically, the strike plate may be curved from top-to bottomand from side-to-side so as to closely conform to a wearer's chestand/or abdomen. The strike plate 12 may be formed in any thickness, andin one embodiment, is between 0.125 and 0.5 inches thick.

The strike plate 12 is preferably formed of a metal matrix compositematerial comprising a metal matrix and a nanocellulose supplement. Themetal matrix forms a base structure and may be a monolithic materialsuch that the metal matrix is continuous throughout the compositematerial. The metal matrix may be formed of aluminum, magnesium,titanium, or other structural metals, or cobalt, cobalt-nickel alloys,steel and ferrous alloys, or other metals for high-temperatureapplications. The metal matrix may be formed from a metal base materialsuch as a powder or feedstock.

The nanocellulose supplement improves properties of the compositematerial and may be microscopic nanocellulose particles dispersedthroughout the metal matrix. The nanocellulose supplement may besubstantially mixed with particles of the metal matrix such that thecomposite material is a homogenous composite. The nanocellulosesupplement may be any form of nano-structured cellulose. This may beeither cellulose nanofibers (CNF), also called microfibrillatedcellulose (MFC), nanocrystalline cellulose (NCC), also calledcrystalline nanocellulose, and bacterial nanocellulose, which refers tonano-structured cellulose produced by bacteria, among others, not tolimit other potential forms or sources of nanocellulose. Thenanocellulose supplement may increase the strength, change porosity ofthe metal matrix, or alter other properties of the composite material10. The nanocellulose supplement may be formed from a nanocellulosesupplement material.

Use of such a metal matrix composite material allows the strike plate 12(and other layers of the body armor plate 10 if formed from the samematerials) to be relatively thin and lightweight while still providingsufficient protection against projectiles. This material also resistscracking and thus provides all or much of its initial protection evenwhen subjected to multiple ballistic strikes in the same area. Theabove-described metal matrix composite material may be used to form thestrike plate and/or other layers of the body armor plate 10 via anadditive manufacturing process described below.

The mesh layer 14 is positioned over the strike plate 12 and has aninner side 32 positioned on the outer strike face of the strike plate 12and an opposite outer side 34. The mesh layer may include the sameconcave reliefs and multi-curved profile as the strike plate 12 so as tomatch the overall shape and size of the strike plate. The mesh layer mayhave any thickness, and in one embodiment, is approximately the samethickness as the strike plate 12, between 0.125 and 0.5 inches thick.

As best shown in FIG. 2, the mesh layer 14 also has a number ofintersecting walls 36 that define a plurality of open cells 38 betweenits inner and outer sides 32, 34. The walls 36 and cells 38 may be in ahoneycomb pattern, grid pattern, or any other repeating or non-repeatingpattern. Any number of cells 38 of any size may be formed in the meshlayer. In one embodiment, the mesh layer has a cell density ofapproximately 12 cells per square inch, and each cell has a volume ofapproximately 0.015 cubic inches.

As illustrated in FIGS. 1 & 2, the mesh layer may also have access holes40 along one or more of its edges through which excess powder may drainafter an additive manufacturing process has been completed. Inembodiments which include expandable foam, these access holes may alsobe used to inject the expandable foam as described in more detail below.

The mesh layer may 14 be co-formed with the strike plate 12 via the sameadditive manufacturing process or may be formed separately and adheredto the strike plate with adhesives or fasteners. Similarly, the meshlayer may be formed of the same metal matrix composite material as thestrike plate or a different material.

The outer skin layer 16 is positioned over the mesh layer 14 and has aninner face 42 and an opposite outer face 44. The outer skin layer 16 maywrap around the edges of the mesh layer 14 so that its inner face 42encapsulates the open cells 38 of the mesh layer 44 between it and thestrike plate 12. The outer skin layer 16 may have any thickness, and inone embodiment, is between 0.025 and 0.0625 inches thick.

The outer skin layer 16 may be co-formed with the strike plate 12 viathe same additive manufacturing process or may be formed separately andadhered to the strike plate. Likewise, the outer skin layer 16 may beformed of the same metal matrix composite material as the strike plateor a different material.

The open cells 38 in the mesh layer 14 entrap air. In other embodiments,foam 18 at least partially fills the open cells 38 in the mesh layer 14.The entrapped air or foam protect against fragmentation. The foam 18 maybe any expandable material. In one embodiment, the foam is injected intothe open cells 38 of the mesh layer 14 via the access holes 40. In otherembodiments, the foam 18 is added to the mesh layer 14 as the mesh layeris fabricated.

Embodiments of the invention may also include a vest or other wearablearticle of clothing for supporting one or more of the above-describedbody armor plates 10 over a wearer's torso or other body part. The bodyarmor plates 10 may also be applied to or embedded within objects suchas vehicle door panels, walls, ceilings, etc.

The above-described body armor plate 10 provides numerous advantages.For example, the layers 12, 14, 16 cooperate to arrest projectilefragments and reduce related injuries. When a projectile strikes thebody armor plate 10, it penetrates, but is slowed by, the outer skinlayer 16 and the mesh layer 14. When it strikes the strike plate 12, itmay fragment, but the fragments are slowed by and trapped within themesh layer 14. This protects the wearer and those nearby fromfragmentation. The mesh layer 14, and the trapped air or foam in themesh layer also improve the negative buoyancy of the body armor plate10.

Methods of forming the metal matrix material used in the body armorplate 10 and fabricating the body armor plate itself are depicted in theflow charts of FIGS. 3 & 4. These flow charts show some of the aspectsof preferred implementations of the present invention. In somealternative implementations, the steps or functions noted in the variousblocks may occur out of the order depicted in the figures. For example,two blocks shown in succession may in fact be performed substantiallyconcurrently, or the steps may be executed in the reverse order or adifferent order.

Exemplary methods for forming the metal matrix materials will now bedescribed with reference to FIG. 3. To form the composite material viaconsolidation such as additive manufacturing, casting, and sintering, ametal base material (e.g., microscopic metal matrix particles) such asmetal powder and a nanocellulose supplement material (e.g., microscopicnanocellulose particles) may be blended together such that thenanocellulose supplement material is dispersed in the metal basematerial as shown in block 100 of FIG. 3. This may be performed viapre-mixing, simultaneous material dispensing, or any other suitabledispersion.

The metal base material and the nanocellulose supplement material maythen be consolidated such as via high temperature consolidation (e.g.,compaction, degassing, and/or thermo-mechanical treatment) such that themetal base material fuses or otherwise bonds together with thenanocellulose supplement material being dispersed throughout the metalmatrix, as shown in block 102. The nanocellulose supplement material maybe heated to a predetermined temperature and/or pressure for apredetermined amount of time for effecting proper fusing of the metalbase material and dispersion of the nanocellulose supplement material.The consolidation may also be performed in a vacuum or under pressure.

The nanocellulose supplement material may be subjected to partialburnout or complete burnout such that at least some of the organicstructure of the nanocellulose supplement material 18 is reduced tocarbon, as shown in block 104. This results in undamaged carbonreinforcing the metal matrix.

The composite material may also be formed via electroplating,electroforming, vapor deposition, and in-situ fabrication. For example,the metal matrix and the nanocellulose supplement may be blended viasolid state, semi-solid state, or liquid state processing. Theparticular nanocellulose supplement material may be selected accordingto the desired improved property of the composite material. The relativepercentage of nanocellulose supplement to metal matrix may also bechosen according to the desired properties of the composite material.For example, more nanocellulose supplement may be used if additionalstrength is desired.

The above-described composite material and method of forming the sameprovide several advantages over conventional composite materials. Forexample, the nanocellulose supplement material 18 can be dispersed inthe metal base material without damage to the nanocellulose supplementmaterial, unlike graphene and carbon nanotubes which become damagedduring formation. The nanocellulose supplement material is also moreeasily dispersed in the metal base material than graphene and carbonnanotubes. The composite material 10 can be formed via additivemanufacturing, casting, and sintering, allowing for the compositematerial to be used in large and small structural, electrical,biochemical, and biomechanical applications. Nanocellulose is also arenewable and readily available resource.

Exemplary methods of forming body armor plates such as the body armorplate10 described above will now be described with reference to FIG. 4.In one embodiment, the body armor plates are fabricated with powder bedfusion additive manufacturing techniques comprising the following steps.First, the strike plate 12 is formed by depositing a metal matrixcomposite material onto a form or other structure as shown in block 200.The strike plate 12 may be formed so as to have a multi-curved profile,an inner face 20, an outer strike face 22, upper corner concave reliefs24, 26, and lower corner concave reliefs 28, 30 as shown in FIG. 2. Thisstep may comprise or be proceeded by the step of designing the shape andmulti-curved profile of the strike plate 12 so it conforms to aparticular wearer's torso or other body part.

Next, the mesh layer 14 is formed by depositing additional metal matrixcomposite material on the strike plate 12 as shown in block 202.Alternatively, the mesh layer 14 may be formed separately from thestrike plate 12 and subsequently glued or otherwise attached to thestrike plate. The mesh layer 14 may be formed so as to have an innerside 32 positioned on the outer strike face 22 of the strike plate 12and an opposite outer side 34. The mesh layer also includes a number ofintersecting walls 36 that define a number of open cells 38. The accessholes 40 in the mesh layer 14 may also be formed in this step.

Next, the outer skin layer 16 is formed by depositing additional metalmatrix composite material on the mesh layer 14 as shown in block 204.Alternatively, the outer skin layer 16 may be formed separately andglued on otherwise attached over the mesh layer 14. The outer skin layer16 is preferably formed so as to extend over the edges of the mesh layer14 to encapsulate the mesh layer 14 between the strike plate 12 and theouter skin layer 16.

During the formation of the layers 12, 14, 16, any unfused metal matrixpowder may drain from the body armor plate via the access holes 40.

In embodiments of the body armor plate that include foam in the meshlayer 14 rather than entrapped air, expandable, buoyant, closed cellfoam 18 is injected in the open cells 38 of the mesh layer 14 asdepicted in block 206. In some embodiments, other materials such asepoxies or polymers may be used instead of foam, and as mentioned above,in some embodiments, only air or other gas is trapped in the open cells38. The foam or other materials may be injected into the open cells viathe access holes 40. The access holes are then sealed with any suitablematerials as depicted in block 208.

Finally, one or more of the fabricated body armor plates 10 is insertedin a vest or other wearable item as depicted in block 210. The plates 10may also be inserted in or attached to walls, door panels, and otherstructures or objects.

Forming some or all of the layers of the body armor plate 10 viaadditive manufacturing as described above permits the body armor platesto be sized and shaped to conform to a particular wearer's physique.Moreover, additive manufacturing permits the thicknesses of the strikeplate 12 and other layers to be selected to provide protection againstdifferent types and speeds of ballistic projectiles. Different portionsof each layer can also be formed in different thickness to provide extraprotection or extra mobility as needed. For example, portions of thelayers 12, 14, 16 configured to cover a wearer's heart maybe relativelythicker for added protection whereas portions of the layers configuredto cover a wearer's hips may be relatively thinner to provide bettermobility.

Additional Considerations

In this description, references to “one embodiment,” “an embodiment,” or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment,” “an embodiment,” or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments but is not necessarily included.Thus, the current technology can include a variety of combinationsand/or integrations of the embodiments described herein.

Although the present application sets forth a detailed description ofnumerous different embodiments, the legal scope of the description isdefined by the words of the claims set forth at the end of this patentand equivalents. The detailed description is to be construed asexemplary only and does not describe every possible embodiment sincedescribing every possible embodiment would be impractical. Numerousalternative embodiments may be implemented, using either currenttechnology or technology developed after the filing date of this patent,which would still fall within the scope of the claims.

Throughout this specification, plural instances may implementcomponents, operations, or structures described as a single instance.Although individual operations of one or more methods are illustratedand described as separate operations, one or more of the individualoperations may be performed concurrently, and nothing requires that theoperations be performed in the order illustrated. Structures andfunctionality presented as separate components in example configurationsmay be implemented as a combined structure or component. Similarly,structures and functionality presented as a single component may beimplemented as separate components. These and other variations,modifications, additions, and improvements fall within the scope of thesubject matter herein.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus.

The patent claims at the end of this patent application are not intendedto be construed under 35 U.S.C. § 112(f) unless traditionalmeans-plus-function language is expressly recited, such as “means for”or “step for” language being explicitly recited in the claim(s).

Although the invention has been described with reference to theembodiments illustrated in the attached drawing figures, it is notedthat equivalents may be employed and substitutions made herein withoutdeparting from the scope of the invention as recited in the claims.

Having thus described various embodiments of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:
 1. A multi-layer armor plate comprising: a strike plateformed of metal matrix composite materials; a mesh layer positioned overthe strike plate, the mesh layer having a number of open cells andcomprising metal matrix composite materials; and an outer skin layerpositioned over the mesh layer so as to encapsulate the open cells ofthe mesh layer between the strike plate and the outer skin layer.
 2. Thearmor plate set forth in claim 1, wherein the strike plate has amulti-curved profile for conforming to a wearer's torso, an inner facefor at least partially covering the wearer's chest, an outer strikeface, upper corner concave reliefs for accommodating the wearer's arms,and lower corner concave reliefs for accommodating the wearer's hips andthighs.
 3. The armor plate set forth in claim 1, wherein the strikeplate is formed via additive manufacturing methods.
 4. The armor plateset forth in claim 1, wherein the metal matrix composite materialscomprise a metal matrix and a nanocellulose supplement.
 5. The armorplate set forth in claim 2, wherein the mesh layer has an inner sidepositioned on the outer strike face of the strike plate and an outerside, with the open cells formed between the inner side and the outerside.
 6. The armor plate set forth in claim 5, wherein the open cells ofthe mesh layer entrap air.
 7. The armor plate set forth in claim 1,wherein the outer skin layer is formed of metal matrix compositematerials.
 8. The armor plate set forth in claim 1, further comprisingexpandable, buoyant foam that at least partially fills the open cells ofthe mesh layer.
 9. A multi-layer, wearable body armor plate comprising:a strike plate formed of metal matrix composite materials and having amulti-curved profile for conforming to the wearer's torso, an inner facefor at least partially covering the wearer's chest, an outer strikeface, upper corner concave reliefs for accommodating the wearer's arms,and lower corner concave reliefs for accommodating the wearer's hips andthighs; a mesh layer formed of metal matrix composite materials andhaving an inner side positioned on the outer strike face of the strikeplate, an outer side, a number of open cells formed between the innerside and outer side, and edges between the inner side and the outerside; and an outer skin layer formed of metal matrix composite materialsand positioned over the outer side and the edges of the mesh layer so asto encapsulate the open cells of the mesh layer between the strike plateand the outer skin layer.
 10. The body armor plate set forth in claim 9,wherein the strike plate is formed via additive manufacturing methodsand has a thickness of 0.125-0.5 inches.
 11. The body armor plate setforth in claim 9, wherein the metal matrix composite materials of atleast one of the strike plate, the mesh layer, or the outer skin layercomprise a metal matrix and a nanocellulose supplement.
 12. The bodyarmor plate set forth in claim 9, wherein the mesh layer has a thicknessof 0.125-0.5 inches.
 13. The body armor plate set forth in claim 12,wherein the open cells of the mesh layer entrap air.
 14. The body armorplate set forth in claim 9, further comprising expandable, buoyant foamthat at least partially fills the open cells of the mesh layer.
 15. Amethod of forming a multi-layer, wearable body armor plate comprising:depositing metal matrix composite materials via additive manufacturingto form a strike plate having an inner face and an outer strike face;depositing additional metal matrix composite materials via additivemanufacturing to form a mesh layer over the strike plate, the mesh layerhaving an inner side positioned on the outer strike face of the strikeplate, an outer side, a number of open cells formed between the innerside and outer side, and edges between the inner side and the outerside; and depositing additional material via additive manufacturing toform an outer skin layer over the outer side and the edges of the meshlayer so as to encapsulate the open cells of the mesh layer between thestrike plate and the outer skin layer.
 16. The method as set forth inclaim 15, wherein the metal matrix composite materials of at least oneof the strike plate or the mesh layer comprises a metal matrix and ananocellulose supplement.
 17. The method as set forth in claim 15,further comprising forming access holes in the mesh layer.
 18. Themethod as set forth in claim 17, further comprising injectingexpandable, buoyant foam in the open cells of the mesh layer.
 19. Themethod as set forth in claim 17, further comprising sealing the accessholes.
 20. The method as set forth in claim 15, wherein the material ofthe outer skin comprises metal matrix composite materials.